<!DOCTYPE html>
<html>

	<head>
		<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
		<meta name="viewport" content="initial-scale=1.0, user-scalable=no">
		<title>首页</title>
		<style>
			#all {
				width: 80%;
				margin-left: auto;
				margin-right: auto;
				text-align: center;
			}
		</style>
	</head>

	<body>
		<div id="all">这是首页</div>
	</body>

</html>